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  • Les formats acceptés

    28 January 2010, by

    Les commandes suivantes permettent d’avoir des informations sur les formats et codecs gérés par l’installation local de ffmpeg :
    ffmpeg -codecs ffmpeg -formats
    Les format videos acceptés en entrée
    Cette liste est non exhaustive, elle met en exergue les principaux formats utilisés : h264 : H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 m4v : raw MPEG-4 video format flv : Flash Video (FLV) / Sorenson Spark / Sorenson H.263 Theora wmv :
    Les formats vidéos de sortie possibles
    Dans un premier temps on (...)

  • Ajouter notes et légendes aux images

    7 February 2011, by

    Pour pouvoir ajouter notes et légendes aux images, la première étape est d’installer le plugin "Légendes".
    Une fois le plugin activé, vous pouvez le configurer dans l’espace de configuration afin de modifier les droits de création / modification et de suppression des notes. Par défaut seuls les administrateurs du site peuvent ajouter des notes aux images.
    Modification lors de l’ajout d’un média
    Lors de l’ajout d’un média de type "image" un nouveau bouton apparait au dessus de la prévisualisation (...)

  • XMP PHP

    13 May 2011, by

    Dixit Wikipedia, XMP signifie :
    Extensible Metadata Platform ou XMP est un format de métadonnées basé sur XML utilisé dans les applications PDF, de photographie et de graphisme. Il a été lancé par Adobe Systems en avril 2001 en étant intégré à la version 5.0 d’Adobe Acrobat.
    Étant basé sur XML, il gère un ensemble de tags dynamiques pour l’utilisation dans le cadre du Web sémantique.
    XMP permet d’enregistrer sous forme d’un document XML des informations relatives à un fichier : titre, auteur, historique (...)

On other websites (3262)

  • ffmpeg record audio from Xvfb on Centos

    25 May 2017, by boygiandi

    I’m trying to record audio from Xvfb. And I have some problems :

    1. What’s the different between alsa and pulse. I get confuse
    2. Server Centos have no soud card:

    arecord -l

    arecord: device_list:268: no soundcards found...

    1. I may have many Xvfb process, how to record video and audio from specific Xvfb process. I checked this https://trac.ffmpeg.org/wiki/Capture/ALSA#Recordaudiofromanapplication but still don’t understand how it works.

    ffmpeg -f alsa -ac 2 -i hw:0,0 -acodec pcm_s16le output.wav

    I seen many command like this, but I don’t know how to get hw:0,0 ( id of sound card ? )

    Please help. Thanks

  • How do I force an IDR-frame using the x264 C API?

    28 October 2020, by Keith

    I am attempting to use an external bool signal to force the next encoded frame to be an IDR-frame using the x264 C API. I am using the "baseline" profile with the "ultrafast" and "zerolatency" presets. I tried to use the input pic settings prior to encoding, as in this code snippet, but this has not worked. My class Open() and Encode() methods are shown here. Any help will be appreciated.

    


    int X264Encoder::Open(void)
{
  if (_x264VideoEncoder != NULL)
    Close();

  // Set up default parameters.
  if (x264_param_default_preset(&_param, _encoderSpeedPreset.c_str(), "zerolatency") < 0)  // 0=success, -1=failed
    { _errStr = "X264Encoder::Open: Default parameter preset failed with " + _encoderSpeedPreset; return(0); }

  // Set non-default params.
  _param.i_bitdepth       = 8;
  _param.i_csp            = _colourSpaceMapping[_colourSpace]; // Input colour space
  if(!_param.i_csp)
    { _errStr = "X264Encoder::Open: Incompatible colour space " + to_string(_colourSpace); return(0); }
  _param.i_width          = _width;
  _param.i_height         = _height;
  _param.i_fps_num        = _videoRateNumerator;
  _param.i_fps_den        = _videoRateDenominator;

  _param.rc.i_bitrate     = _avgBitsPerSecond / 1000; // bitrate units are in kbits/s

  _param.i_threads        = 1;
  _param.b_vfr_input      = 0;  // VFR input.  If 1, use timebase and timestamps for ratecontrol purposes. If 0, use fps only.
  _param.b_repeat_headers = 1;  // Put SPS/PPS before each keyframe
  _param.b_annexb         = 1;  // If set, place start codes (4 bytes) before NAL units, otherwise place size (4 bytes) before NAL units.

  // Apply profile restrictions.
  if (x264_param_apply_profile(&_param, _profile.c_str()) < 0)  // 0=success, -1=failed
    { _errStr = "X264Encoder::Open: Unable to set profile " + _profile; return(0); }

  // Initialise the encoder input pic buffer.
  if (x264_picture_alloc(&_picIn, _param.i_csp, _param.i_width, _param.i_height) < 0)
    { _errStr = "X264Encoder::Open: Unable to alloc input picture buffer"; return(0); }
  _inPicIsAllocated = true;

  // Instantiate the encoder.
  _x264VideoEncoder = x264_encoder_open(&_param);
  if (_x264VideoEncoder == NULL)
  {
    _errStr = "X264Encoder::Open: Unable to instantiate the encoder"; 
    // Clean up before exit.
    x264_picture_clean(&_picIn);
    _inPicIsAllocated = false;
    return(0);
  }//end if !_x264VideoEncoder...

  // Frame counting for pts timestamps.
  _frameNum     = 0;
  _lastPicType  = 0; // IDR-frame

  d.clear();

  return(1);
}//end Open.

int X264Encoder::Encode(void* pSrc, void* pCmp, void* codeParameter)
{
  _encodedFrameSize = 0;

  // Validation house work.
  if(!Ready())
    { _errStr = "X264Encoder::Encode: Not ready"; return(0); }

  if(!pSrc || !pCmp)
    { _errStr = "X264Encoder::Encode: Invalid function parameter list"; return(0); }

  // Load input image. 
  if(_param.i_csp != X264_CSP_I420) // Can only process I420 input colour space.
    { _errStr = "X264Encoder::Encode: I420 colour space required"; return(0); }
  uint32_t lumSize = _width * _height;
  uint32_t chrSize = lumSize / 4;
  // Transfer the input source image into the x264 picture img structure.
  uint8_t* pImg = static_cast(pSrc);
  memcpy_s(_picIn.img.plane[0], lumSize, pImg, lumSize);
  pImg += lumSize;
  memcpy_s(_picIn.img.plane[1], chrSize, pImg, chrSize);
  pImg += chrSize;
  memcpy_s(_picIn.img.plane[2], chrSize, pImg, chrSize);

  // Encode single frame
  _picIn.i_pts = _frameNum;
  if (_idrFrameRequired) 
  {  
    _picIn.i_type = X264_TYPE_IDR; 
    //... and clear the signal.
    _idrFrameRequired = false; 
  }//end if _idrFrameRequired...
  else 
    _picIn.i_type = X264_TYPE_AUTO;

  _encodedFrameSize = x264_encoder_encode(_x264VideoEncoder, &_nal, &_nalCnt, &_picIn, &_picOut);
  if (_encodedFrameSize > 0)
  {
    // Write the encoded stream to the output.
    uint8_t* pOut = static_cast(pCmp);
    memcpy_s(pOut, _encodedFrameSize, _nal->p_payload, _encodedFrameSize);
  }//end else if _encodedFrameSize...
  else
    { _errStr = "X264Encoder::Encode: Encode process failed"; return(0); }

  _lastPicType = 1; // Non-IDR
  if (_picOut.i_type == X264_TYPE_IDR)
    _lastPicType = 0; // IDR

  d.push_back({ _encodedFrameSize, _lastPicType });

  _frameNum++;
  return(1);
}//end Encode...


    


  • How do I force an IDR-frame using the x264 C API?

    28 October 2020, by Keith

    I am attempting to use an external bool signal to force the next encoded frame to be an IDR-frame using the x264 C API. I am using the "baseline" profile with the "ultrafast" and "zerolatency" presets. I tried to use the input pic settings prior to encoding, as in this code snippet, but this has not worked. My class Open() and Encode() methods are shown here. Any help will be appreciated.

    


    int X264Encoder::Open(void)
{
  if (_x264VideoEncoder != NULL)
    Close();

  // Set up default parameters.
  if (x264_param_default_preset(&_param, _encoderSpeedPreset.c_str(), "zerolatency") < 0)  // 0=success, -1=failed
    { _errStr = "X264Encoder::Open: Default parameter preset failed with " + _encoderSpeedPreset; return(0); }

  // Set non-default params.
  _param.i_bitdepth       = 8;
  _param.i_csp            = _colourSpaceMapping[_colourSpace]; // Input colour space
  if(!_param.i_csp)
    { _errStr = "X264Encoder::Open: Incompatible colour space " + to_string(_colourSpace); return(0); }
  _param.i_width          = _width;
  _param.i_height         = _height;
  _param.i_fps_num        = _videoRateNumerator;
  _param.i_fps_den        = _videoRateDenominator;

  _param.rc.i_bitrate     = _avgBitsPerSecond / 1000; // bitrate units are in kbits/s

  _param.i_threads        = 1;
  _param.b_vfr_input      = 0;  // VFR input.  If 1, use timebase and timestamps for ratecontrol purposes. If 0, use fps only.
  _param.b_repeat_headers = 1;  // Put SPS/PPS before each keyframe
  _param.b_annexb         = 1;  // If set, place start codes (4 bytes) before NAL units, otherwise place size (4 bytes) before NAL units.

  // Apply profile restrictions.
  if (x264_param_apply_profile(&_param, _profile.c_str()) < 0)  // 0=success, -1=failed
    { _errStr = "X264Encoder::Open: Unable to set profile " + _profile; return(0); }

  // Initialise the encoder input pic buffer.
  if (x264_picture_alloc(&_picIn, _param.i_csp, _param.i_width, _param.i_height) < 0)
    { _errStr = "X264Encoder::Open: Unable to alloc input picture buffer"; return(0); }
  _inPicIsAllocated = true;

  // Instantiate the encoder.
  _x264VideoEncoder = x264_encoder_open(&_param);
  if (_x264VideoEncoder == NULL)
  {
    _errStr = "X264Encoder::Open: Unable to instantiate the encoder"; 
    // Clean up before exit.
    x264_picture_clean(&_picIn);
    _inPicIsAllocated = false;
    return(0);
  }//end if !_x264VideoEncoder...

  // Frame counting for pts timestamps.
  _frameNum     = 0;
  _lastPicType  = 0; // IDR-frame

  d.clear();

  return(1);
}//end Open.

int X264Encoder::Encode(void* pSrc, void* pCmp, void* codeParameter)
{
  _encodedFrameSize = 0;

  // Validation house work.
  if(!Ready())
    { _errStr = "X264Encoder::Encode: Not ready"; return(0); }

  if(!pSrc || !pCmp)
    { _errStr = "X264Encoder::Encode: Invalid function parameter list"; return(0); }

  // Load input image. 
  if(_param.i_csp != X264_CSP_I420) // Can only process I420 input colour space.
    { _errStr = "X264Encoder::Encode: I420 colour space required"; return(0); }
  uint32_t lumSize = _width * _height;
  uint32_t chrSize = lumSize / 4;
  // Transfer the input source image into the x264 picture img structure.
  uint8_t* pImg = static_cast(pSrc);
  memcpy_s(_picIn.img.plane[0], lumSize, pImg, lumSize);
  pImg += lumSize;
  memcpy_s(_picIn.img.plane[1], chrSize, pImg, chrSize);
  pImg += chrSize;
  memcpy_s(_picIn.img.plane[2], chrSize, pImg, chrSize);

  // Encode single frame
  _picIn.i_pts = _frameNum;
  if (_idrFrameRequired) 
  {  
    _picIn.i_type = X264_TYPE_IDR; 
    //... and clear the signal.
    _idrFrameRequired = false; 
  }//end if _idrFrameRequired...
  else 
    _picIn.i_type = X264_TYPE_AUTO;

  _encodedFrameSize = x264_encoder_encode(_x264VideoEncoder, &_nal, &_nalCnt, &_picIn, &_picOut);
  if (_encodedFrameSize > 0)
  {
    // Write the encoded stream to the output.
    uint8_t* pOut = static_cast(pCmp);
    memcpy_s(pOut, _encodedFrameSize, _nal->p_payload, _encodedFrameSize);
  }//end else if _encodedFrameSize...
  else
    { _errStr = "X264Encoder::Encode: Encode process failed"; return(0); }

  _lastPicType = 1; // Non-IDR
  if (_picOut.i_type == X264_TYPE_IDR)
    _lastPicType = 0; // IDR

  d.push_back({ _encodedFrameSize, _lastPicType });

  _frameNum++;
  return(1);
}//end Encode...


    


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